As the innovation of the digital photographing technology in recent years, various electronic devices (such as digital camera, digital video, notebook and mobile phone etc.) equipped with digital photographing component keep emerging. Not only the quality of the photos are getting much better, but the size of the devices become more compact and the prices thereof are getting cheaper as well which make said electronic photographing devices more and more popular. Therefore, to develop an electronic device with intellectual photographing function that fulfills the basic photographic requirements of most of the users and is capable of compensating the lack of photographing technique has become the current trend of the designers and manufacturers of all kinds of electronic photographing devices.
Generally, the conventional electronic photographing device is mainly used to take portrait photos. When taking a portrait photo, the conventional electronic photographing device will try to capture the most appropriate photo by constantly scanning the human face in order to present the best appearance of the model. And to most of the users, the best appearance of the model is that the model keeps a smiley face and with the eyes opened. Therefore, when taking a portrait photo, the photographer is expected to capture the moment that the model has a smile on the face. However, due to lack of communication or mutual understanding, the model is often not aware of the moment that the photographer takes the photo which leads to closed eyes and unnatural expressions. Even when the model is informed to keep the smiley face for taking the photo, still the model could closed the eyes unexpectedly for being unable to maintain the same expression for a long time, thus makes a smiley face turn into an unnatural expression. And all these cases will lead to portrait photos with unnatural or plain expressions and aren't well satisfying. Especially when taking photos of various people or children, the problems stated above are nearly inevitable, and it will be such a great pity without a well-shot photo for the memorable day. Thus, it is the major objective of the designers and manufacturers of all kinds of electronic photographing devices to develop a photo restoration technique which enables the electronic photographing device to determine whether the portrait photo taken is with the eyes closed and to proceed an automatic restoration process to restore the unnatural expression to a normal one when it is determined that the eyes are closed, such as to automatically restore a closed-eye portrait photo to an open-eye portrait photo, thereby ensures the quality of each portrait photo generated and substantially increases the possibility of making a well-shot photo.